Role of antioxidant activity of taurine in diabetes

Multifunctional Hydrogel Microneedle Patches Modulating Oxi-inflamm-aging for Diabetic Wound Healing

Oxidative stress, chronic inflammation, and immune senescence are important pathologic factors in diabetic wound nonhealing. This study loads taurine (Tau) into cerium dioxide (CeO2) to develop CeO2@Tau nanoparticles with excellent antioxidant, anti-inflammatory, and anti-aging properties. To enhance the drug penetration efficiency in wounds, CeO2@Tau is encapsulated in gelatin methacryloyl (GelMA) hydrogel to prepare CeO2@Tau@Hydrogel@Microneedle (CTH@MN) patch system. Microneedle technology achieves precise and efficient delivery of CeO2@Tau, ensuring their deep penetration into the wound tissue for optimal efficacy. Rigorous in vitro and in vivo tests have confirmed the satisfactory therapeutic effect of CTH@MN patch on diabetic wound healing. Mechanistically, CTH@MN attenuates oxidative damage and inflammatory responses in macrophages by inhibiting the ROS/NF-κB signaling pathway. Meanwhile, CTH@MN activated autophagy-mediated anti-aging activity, creating a favorable immune microenvironment for tissue repair. Notably, in a diabetic mouse wound model, the multifunctional CTH@MN patch significantly promotes wound healing by systematically regulating the oxidation-inflammation-aging (oxi-inflamm-aging) pathological axis. In conclusion, the in-depth exploration of the CTH@MN system in this study provides new strategies and perspectives for treating diabetic non-healing wounds.

The Role of Bioactive Small Molecules in COPD Pathogenesis

Chronic obstructive pulmonary disease (COPD) is recognized as a predominant contributor to mortality worldwide, which causes significant burdens to both society and individuals. Given the limited treatment options for COPD, there lies a critical realization: the imperative for expeditious development of novel therapeutic modalities that can effectively alleviate disease progression and enhance the quality of life experienced by COPD patients. Within the intricate field of COPD pathogenesis, an assortment of biologically active small molecules, encompassing small protein molecules and their derivatives, assumes crucial roles through diverse mechanisms. These mechanisms relate to the regulation of redox balance, the inhibition of the release of inflammatory mediators, and the modulation of cellular functions. Therefore, the present article aims to explore and elucidate the distinct roles played by different categories of biologically active small molecules in contributing to the pathogenesis of COPD.

Assessment of Protective Effects of DTPA, NAC, and Taurine on Possible Cytotoxicity Induced by Individual and Combined Zinc Oxide and Copper Oxide Nanoparticles in SH-SY5Y Cells

The present study investigated the cytotoxic effects of ZnO, CuO, and mixed combinations of them on SH-SY5Y cells. For this purpose, the cells were exposed to various concentrations of these NPs alone for 24-96 h and as a mixture for 24 h. Variations in cell viability were noted. MTT results showed that ZnO and/or CuO NPs decreased cell survival by about 59% at 200 (ZnO, at 24 h) and 800 µg/ml (ZnO and/or CuO, at 72 and 96 h). When the NR assay was used, slight decreases were noted with ZnO NPs at 72 and 96 h. With CuO NPs alone and NPs in a mixture, only the highest concentrations caused 40 and 70% decreases in cell survival, respectively. Especially with NR assays, DTPA, NAC, or taurine provided marked protection. ROS levels were increased with the highest concentration of CuO NPs and with all concentrations of the mixture. The highest concentration of ZnO NPs and the lowest concentration of CuO NPs caused slight decreases in mitochondrial membrane potential levels. Additionally, increases were noted in caspase 3/7 levels with ZnO and CuO NPs alone or with a mixture of them. Intracellular calcium levels were decreased in this system. These findings demonstrated that ZnO and CuO NPs, either separately or in combination, had a modest cytotoxic effect on SH-SY5Y cells. Protection obtained with DTPA, NAC, or taurine against the cytotoxicity of these NPs and the ROS-inducing effect of CuO NPs and the NPs' mixture suggests that oxidative stress might be involved in the cytotoxicity mechanisms of these NPs.

Taurine amino acid supplementation impacts performance, blood hematology, oxidative stress, and jejunum morphology in broiler chickens

Excess levels of free radicals cause oxidative damage to cells. Taurine is a rare amino acid with antioxidant effects whose dietary deficiency increases oxidative damage to the cell membrane. To investigate the effects of dietary taurine supplementation on performance, blood hematology, oxidative stress, and jejunum morphology in broilers, 300 broilers (Ras 308, 1D of age) were randomly allocated into 4 groups with 5 replicates of 15 birds. The experimental treatments included basic diet (control treatment) and basic diet with 1, 3, and 6 g/kg taurine amino acid. During 1 to 45 days, the inclusion of taurine supplementation in diets improved the body weight gain (BWG), feed consumption (FC), and feed conversion ratio (FCR) of broilers (P < 0.05). In CBC tests, the experimental treatments were significantly different concerning the red blood cell (RBC) count, the average hemoglobin in the cell, the RBC width in the curve, and the hematocrit (P < 0.05). Despite the significance of oxidative stress among the treatments, the control and fourth treatments showed the highest and the lowest oxidative stress, respectively (P < 0.05). Also, in jejunum morphology, the fourth treatment showed the best performance in terms of villus length and width and the villus length to crypt depth (V/C) ratio (P < 0.05). Overall, 6 g/kg taurine addition to the diet reduced oxidative stress and positive features in the jejunum morphology while improving the functional traits of broilers.

Association Between Taurine Level in the Hippocampus and Major Depressive Disorder in Young Women: A Proton Magnetic Resonance Spectroscopy Study at 7T

BACKGROUND

Major depressive disorder (MDD) is characterized by depressed mood or loss of interest or pleasure. Generally, women are twice as likely as men to have depression. Taurine, a type of amino acid, plays critical roles in neuronal generation, differentiation, arborization, and formation of synaptic connections. Importantly, it enhances proliferation and synaptogenesis in the hippocampus. When injected into animals, taurine has an antidepressant effect. However, there is no in vivo evidence to show an association between taurine concentration in the human brain and the development of MDD.

METHODS

Forty-one unmedicated young women with MDD (ages 18-29) and 43 healthy control participants matched for gender and age were recruited in South Korea. Taurine concentration was measured in the hippocampus, anterior cingulate cortex, and occipital cortex of the MDD and healthy control groups using proton magnetic resonance spectroscopy at 7T. Analysis of covariance was used to examine differences in taurine concentration, adjusting for age as a covariate.

RESULTS

Taurine concentration in the hippocampus was lower (F1,75 = 5.729, p = .019, Δη2 = 0.073) for the MDD group (mean [SEM] = 0.91 [0.06] mM) than for the healthy control group (1.13 [0.06] mM). There was no significant difference in taurine concentration in the anterior cingulate cortex or occipital cortex between the two groups.

CONCLUSIONS

This study demonstrates that a lower level of taurine concentration in the hippocampus may be a novel characteristic of MDD.

Taurine deficiency associated with dilated cardiomyopathy and aging

Taurine (2-aminoethanesulfonic acid) is a free amino acid found ubiquitously and abundantly in mammalian tissues. Taurine content in the heart is approximately 20 mM, which is approximately 100 times higher than plasma concentration. The high intracellular concentration of taurine is maintained by the taurine transporter (TauT; Slc6a6). Taurine plays various roles, including the regulation of intracellular ion dynamics, calcium handling, and acting as an antioxidant in the heart. Some species, such as cats and foxes, have low taurine biosynthetic capacity, and dietary taurine deficiency can lead to disorders such as dilated cardiomyopathy and blindness. In humans, the relationship between dietary taurine deficiency and cardiomyopathy is not yet clear, but a genetic mutation related to the taurine transporter has been reported to be associated with dilated cardiomyopathy. On the other hand, many studies have shown an association between dietary taurine intake and age-related diseases. Notably, it has recently been reported that taurine declines with age and is associated with lifespan in worms and mice, as well as healthspan in mice and monkeys. In this review, we summarize the role of dietary and genetic taurine deficiency in the development of cardiomyopathy and aging.

An Integrated Metabolomics-Based Model, and Identification of Potential Biomarkers, of Perfluorooctane Sulfonic Acid Toxicity in Zebrafish Embryos

Known for their high stability and surfactant properties, per- and polyfluoroalkyl substances (PFAS) have been widely used in a range of manufactured products. Despite being largely phased out due to concerns regarding their persistence, bioaccumulation, and toxicity, legacy PFAS such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid continue to persist at high levels in the environment, posing risks to aquatic organisms. We used high-resolution magic angle spinning nuclear magnetic resonance spectroscopy in intact zebrafish (Danio rerio) embryos to investigate the metabolic pathways altered by PFOS both before and after hatching (i.e., 24 and 72 h post fertilization [hpf], respectively). Assessment of embryotoxicity found embryo lethality in the parts-per-million range with no significant difference in mortality between the 24- and 72-hpf exposure groups. Metabolic profiling revealed mostly consistent changes between the two exposure groups, with altered metabolites generally associated with oxidative stress, lipid metabolism, energy production, and mitochondrial function, as well as specific targeting of the liver and central nervous system as key systems. These metabolic changes were further supported by analyses of tissue-specific production of reactive oxygen species, as well as nontargeted mass spectrometric lipid profiling. Our findings suggest that PFOS-induced metabolic changes in zebrafish embryos may be mediated through previously described interactions with regulatory and transcription factors leading to disruption of mitochondrial function and energy metabolism. The present study proposes a systems-level model of PFOS toxicity in early life stages of zebrafish, and also identifies potential biomarkers of effect and exposure for improved environmental biomonitoring. Environ Toxicol Chem 2024;00:1-19. © 2024 SETAC.

Taurine Supplementation for 48-Months Improved Glucose Tolerance and Changed ATP-Related Enzymes in Avians

Avians differ from mammals, especially in brain architecture and metabolism. Taurine, an amino acid basic to metabolism and bioenergetics, has been shown to have remarkable effects on metabolic syndrome and ameliorating oxidative stress reactions across species. However, less is known regarding these metabolic relationships in the avian model. The present study serves as a preliminary report that examined how taurine might affect avian metabolism in an aged model system. Two groups of pigeons (Columba livia) of mixed sex, a control group and a group that received 48 months of taurine supplementation (0.05% w/v) in their drinking water, were compared by using blood panels drawn from their basilic vein by a licensed veterinarian. From the blood panel data, taurine treatment generated higher levels of three ATP-related enzymes: glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH), and creatine kinase (CK). In this preliminary study, the role that taurine treatment might play in the adult aged pigeon's metabolism on conserved traits such as augmenting insulin production as well as non-conserved traits maintaining high levels of ATP-related enzymes was examined. It was found that taurine treatment influenced the avian glucose metabolism similar to mammals but differentially effected avian ATP-related enzymes in a unique way (i.e., ∼×2 increase in CK and LDH with a nearly ×4 increase in GLDH). Notably, long-term supplementation with taurine had no negative effect on parameters of lipid and protein metabolism nor liver enzymes. The preliminary study suggests that avians may serve as a unique model system for investigating taurine metabolism across aging with long-term health implications (e.g., hyperinsulinemia). However, the suitability of using the model would require researchers to tightly control for age, sex, dietary intake, and exercise conditions as laboratory-housed avian present with very different metabolic panels than free-flight avians, and their metabolic profile may not correlate one-to-one with mammalian data.

Bibliometric and Visual Analysis of Global Research on Taurine, Creatine, Carnosine, and Anserine with Metabolic Syndrome: From 1992 to 2022

Red meat and animal-sourced protein are often disparaged as risk factors for developing metabolic syndrome, while emerging research has shown the beneficial effects of dietary taurine, creatine, carnosine, and anserine which are all exclusively abundant in red meat. Thus, it is imperative to highlight the available evidence to help promote red meat as part of a well-balanced diet to optimize human health. In this study, a bibliometric analysis was conducted to investigate the current research status of dietary taurine, creatine, carnosine, and anserine with metabolic syndrome, identify research hotspots, and delineate developmental trends by utilizing the visualization software CiteSpace. A total of 1094 publications were retrieved via the Web of Science Core Collection from 1992 to 2022. There exists a gradual increase in the number of publications on this topic, but there is still much room for research papers to rise. The United States has participated in the most studies, followed by China and Japan. The University of Sao Paulo was the research institute contributing the most; Kyung Ja Chang and Sanya Roysommuti have been identified as the most prolific authors. The analysis of keywords reveals that obesity, lipid profiles, blood pressure, and glucose metabolism, as well as ergogenic aid and growth promoter have been the research hotspots. Inflammation and diabetic nephropathy will likely be frontiers of future research related to dietary taurine, creatine, carnosine, and anserine. Overall, this paper may provide insights for researchers to further delve into this field and enlist the greater community to re-evaluate the health effects of red meat.

Metabolomics for the identification of early biomarkers of nephrotoxicity in a mouse model of cisplatin-induced acute kidney injury

BACKGROUND AND PURPOSE

Cisplatin-induced nephrotoxicity manifests as acute kidney injury (AKI) in approximately one third of patients receiving cisplatin therapy. Current measures of AKI are inadequate in detecting AKI prior to significant renal injury, and better biomarkers are needed for early diagnosis of cisplatin-induced AKI.

EXPERIMENTAL APPROACH

C57BL/6 and FVB/N mice were treated with a single intraperitoneal injection of cisplatin (15 mg kg-1) or saline. Plasma, urine, and kidney samples were collected prior to cisplatin injection and 24-, 48-, 72-, and 96-hours following cisplatin injection. Untargeted metabolomics was employed using liquid chromatography-mass spectrometry to identify early diagnostic biomarkers for cisplatin nephrotoxicity.

PRINCIPAL RESULTS

There was clear metabolic discrimination between saline and cisplatin-treated mice at all timepoints (day 1 to day 4). In total, 26 plasma, urine, and kidney metabolites were identified as exhibiting early alterations following cisplatin treatment. Several of the metabolites showing early alterations were associated with mitochondrial function and energetics, including intermediates of the tricarboxylic acid cycle, regulators of mitochondrial function and indicators of fatty acid β-oxidation dysfunction. Furthermore, several metabolites were derived from the gut microbiome.

MAJOR CONCLUSIONS

Our results highlight the detrimental effects of cisplatin on mitochondrial function and demonstrate potential involvement of the gut microbiome in the pathophysiology of cisplatin-induced AKI. We provide a panel of metabolites to guide future clinical studies of cisplatin-induced AKI and provide insight into potential mechanisms behind cisplatin nephrotoxicity.

Metabolites, gene expression, and gut microbiota profiles suggest the putative mechanisms via which dietary creatine increases the serum taurine and g-ABA contents in Megalobrama amblycephala

A 90-day experiment was conducted to explore the effects of creatine on growth performance, liver health status, metabolites, and gut microbiota in Megalobrama amblycephala. There were 6 treatments as follows: control (CD, 29.41% carbohydrates), high carbohydrate (HCD, 38.14% carbohydrates), betaine (BET, 1.2% betaine + 39.76% carbohydrates), creatine 1 (CRE1, 0.5% creatine + 1.2% betaine + 39.29% carbohydrates), creatine 2 (CRE2, 1% creatine + 1.2% betaine + 39.50% carbohydrates), and creatine 3 (CRE3, 2% creatine + 1.2% betaine + 39.44% carbohydrates). The results showed that supplementing creatine and betaine together reduced the feed conversion ratio significantly (P < 0.05, compared to CD and HCD) and improved liver health (compared to HCD). Compared with the BET group, dietary creatine significantly increased the abundances of Firmicutes, Bacteroidota, ZOR0006, and Bacteroides and decreased the abundances of Proteobacteria, Fusobacteriota, Vibrio, Crenobacter, and Shewanella in the CRE1 group. Dietary creatine increased the content of taurine, arginine, ornithine, γ-aminobutyric acid (g-ABA), and creatine (CRE1 vs. BET group) and the expression of creatine kinase (ck), sulfinoalanine decarboxylase (csad), guanidinoacetate N-methyltransferase (gamt), glycine amidinotransferase (gatm), agmatinase (agmat), diamine oxidase1 (aoc1), and glutamate decarboxylase (gad) in the CRE1 group. Overall, these results suggested that dietary supplementation of creatine (0.5-2%) did not affect the growth performance, but it altered the gut microbial composition at the phylum and genus levels, which might be beneficial to the gut health of M. amblycephala; dietary creatine also increased the serum content of taurine by enhancing the expressions of ck and csad and increased the serum content of g-ABA by enhancing the arginine content and the expressions of gatm, agmat, gad, and aoc1.

Status of Metabolomic Measurement for Insights in Alzheimer's Disease Progression-What Is Missing?

Alzheimer's disease (AD) is an aging-related neurodegenerative disease, leading to the progressive loss of memory and other cognitive functions. As there is still no cure for AD, the growth in the number of susceptible individuals represents a major emerging threat to public health. Currently, the pathogenesis and etiology of AD remain poorly understood, while no efficient treatments are available to slow down the degenerative effects of AD. Metabolomics allows the study of biochemical alterations in pathological processes which may be involved in AD progression and to discover new therapeutic targets. In this review, we summarized and analyzed the results from studies on metabolomics analysis performed in biological samples of AD subjects and AD animal models. Then this information was analyzed by using MetaboAnalyst to find the disturbed pathways among different sample types in human and animal models at different disease stages. We discuss the underlying biochemical mechanisms involved, and the extent to which they could impact the specific hallmarks of AD. Then we identify gaps and challenges and provide recommendations for future metabolomics approaches to better understand AD pathogenesis.

Hippocampal region-specific endogenous neuroprotection as an approach in the search for new neuroprotective strategies in ischemic stroke. Fiction or fact?

Ischemic stroke is the leading cause of death and long-term disability worldwide, and, while considerable progress has been made in understanding its pathophysiology, the lack of effective treatments remains a major concern. In that context, receiving more and more consideration as a promising therapeutic method is the activation of natural adaptive mechanisms (endogenous neuroprotection) - an approach that seeks to enhance and/or stimulate the endogenous processes of plasticity and protection of the neuronal system that trigger the brain's intrinsic capacity for self-defence. Ischemic preconditioning is a classic example of endogenous neuroprotection, being the process by which one or more brief, non-damaging episodes of ischemia-reperfusion (I/R) induce tissue resistance to subsequent prolonged, damaging ischemia. Another less-known example is resistance to an I/R episode mounted by the hippocampal region consisting of CA2, CA3, CA4 and the dentate gyrus (here abbreviated to CA2-4, DG). This can be contrasted with the ischemia-vulnerable CA1 region. There is not yet a good understanding of these different sensitivities of the hippocampal regions, and hence of the endogenous neuroprotection characteristic of CA2-4, DG. However, this region is widely reported to have properties distinct from CA1, and capable of generating resistance to an I/R episode. These include activation of neurotrophic and neuroprotective factors, greater activation of anti-excitotoxic and anti-oxidant mechanisms, increased plasticity potential, a greater energy reserve and improved mitochondrial function. This review seeks to summarize properties of CA2-4, DG in the context of endogenous neuroprotection, and then to assess the potential utility of these properties to therapeutic approaches. In so doing, it appears to represent the first such addressing of the issue of ischemia resistance attributable to CA2-4, DG.

Eating more sardines instead of fish oil supplementation: Beyond omega-3 polyunsaturated fatty acids, a matrix of nutrients with cardiovascular benefits

Omega-3 polyunsaturated fatty acids (n-3 PUFA) play a significant role in the prevention and management of cardiometabolic diseases associated with a mild chronic pro-inflammatory background, including type 2 diabetes, hypertension, hypertriglyceridaemia, and fatty liver disease. The effects of n-3 PUFA supplements specifically, remain controversial regarding reducing risks of cardiovascular events. n-3 PUFA supplements come at a cost for the consumer and can result in polypharmacy for patients on pharmacotherapy. Sardines are a well-known, inexpensive source of n-3 PUFA and their consumption could reduce the need for n-3 PUFA supplementation. Moreover, sardines contain other cardioprotective nutrients, although further insights are crucial to translate a recommendation for sardine consumption into clinical practice. The present review discusses the matrix of nutrients contained in sardines which confer health benefits for cardiometabolism, beyond n-3 PUFA. Sardines contain calcium, potassium, magnesium, zinc, iron, taurine, arginine and other nutrients which together modulate mild inflammation and exacerbated oxidative stress observed in cardiovascular disease and in haemodynamic dysfunction. In a common serving of sardines, calcium, potassium, and magnesium are the minerals at higher amounts to elicit clinical benefits, whilst other nutrients are present in lower but valuable amounts. A pragmatic approach towards the consumption of such nutrients in the clinical scenario should be adopted to consider the dose-response relationship effects on physiological interactions. As most recommendations currently available are based on an indirect rationale of the physiological actions of the nutrients found in sardines, randomised clinical trials are warranted to expand the evidence on the benefits of sardine consumption.

Effect of substitution of taurine for methionine and additional taurine supplementation on the performance and antioxidative capacity of laying hens

Taurine (TAU), a sulfur-containing amino acid that synthesized from methionine and cystine, plays vital roles in maintenance of redox balance. The effect of substitution of TAU for methionine was evaluated in vivo and in vitro. The effects of replacing methionine with TAU and additional TAU supplementation on the performance and antioxidant capacity of laying hens were evaluated. The in vitro cultured chicken primary hepatocytes and intestinal epithelial cells were further employed. Two hubdred eighty-eight 40-wk-old Isa brown laying hens were divided into 4 groups and subjected one to the following treatments: fed with basal diet with 0.17% crystallized DL-Met (CON), the control diet and replace 25% (21% total Met, 21TAU) or 50% (42% total Met, 42TAU) of crystallized DL-Met with taurine, the control diet supplemented with 0.1% taurine (0.1% TAU). The laying rate, feed intake, egg weight, and feed efficiency were not influenced (P > 0.05) by TAU replacement or additional TAU supplementation. In the liver, 0.1% TAU decreased SOD but increased GSH-Px activity (P < 0.01). In duodenum, 42TAU decreased SOD activity (P < 0.05) while 0.1% TAU decreased GSH level and SOD activity (P < 0.05). In the hepatocytes, TAU treatment decreased (P < 0.05) the MDA and GSH contents, whereas increased SOD and GSH-Px activities (P < 0.05). Meanwhile, TAU treatment decreased (P < 0.05) the protein expression of Nrf2 while increase Keap1 expression. The mRNA expression of Nrf2, SOD1, SOD2, CAT, and GCLC were increased (P < 0.05) and GSR were decreased (P < 0.05) by 0.1% TAU. In the intestinal epithelial cells, TAU treatment decreased (P < 0.05) SOD activity, increased (P < 0.05) CAT activity, and decreased (P < 0.05) the mRNA and protein expression of Nrf2. In summary, partial substitution methionine for taurine (21-42%) has no influence on egg performance of hens. Taurine enhances the antioxidative capacity in hepatocyte but not in the enterocytes and if taurine could offer an improved effect on antioxidant capacity needs to be verified under oxidative stress-challenged conditions.

Protective and therapeutic effectiveness of taurine supplementation plus low calorie diet on metabolic parameters and endothelial markers in patients with diabetes mellitus: a randomized, clinical trial

Background

Taurine supplementation as a sulfur-containing amino acid may attenuate and/or alleviate diabetes-induced complications and endothelial dysfunction via its anti-inflammatory and antioxidant activities. Our purpose was to investigate the effect of Taurine supplementation on endothelial dysfunction markers, oxidative stress, inflammation, and glycemic control in patients with type 2 diabetes mellitus (T2DM).

Methods

In the current clinical trial, 120 patients with T2DM were randomly allocated to take either Taurine (containing 1 g Taurine, n = 60) or placebo (n = 60) three times per day for an eight-week period. Moreover, all patients were on a low-calorie diet. The primary outcome was fasting blood glucose (FBG) and endothelial markers including sera intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule (VCAM), and matrix metallopeptidase 9 (MMP-9). The secondary outcome was dietary intake, anthropometric indices, serum insulin and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), total antioxidant capacity (TAC), tumor necrosis factor (TNF), high-sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), and lipid profile.

Results

After 8 weeks, Taurine-supplemented patients had a considerable decrease in serum insulin and HOMA-IR compared to placebo group. However, Taurine supplementation did not improve other metabolic parameters including lipid profiles, glycated hemoglobin, and fasting blood glucose (FBG). There was a significant decline in MDA, TNF, and hs-CRP levels after these eight-week period of Taurine supplementation. In addition, the Taurine group had fewer serum levels of endothelial dysfunction markers than the placebo group.

Conclusions

The evidence from our study revealed that Taurine supplementation significantly reduced insulin and HOMA-IR, as well as oxidative stress, inflammation, and endothelial markers in individuals with T2DM.

Trial registration The protocol of the study was recorded in the Iranian Registry of Clinical Trials (IRCT20180712040438N3).

Effect of taurine on glycaemic, lipid and inflammatory profile in individuals with type 2 diabetes: study protocol of a randomised trial

Type 2 diabetes mellitus (T2DM) is characterised by chronic hyperglycaemia. Despite the efficacy of conventional pharmacotherapy, some individuals do not reach glycaemic goals and require adjuvant therapies. Taurine, a semi-essential amino acid, decreases blood glucose and cholesterol levels in rodents and humans. However, glycated hemoglobin (HbA1c) has not been evaluated in randomised controlled trials after taurine treatment for more than 12 weeks. This study aims to evaluate the effect of taurine administration on glycaemic, lipid, inflammatory, anthropometric and dietary parameters in individuals with T2DM. A randomised, double-blind, placebo-controlled clinical trial will be conducted at the Clinical Research Center of a tertiary public hospital. Participants with T2DM (n 94) will be recruited and randomised to receive 3 g of taurine or placebo, twice/day, orally, for 12 weeks. Blood samples will be collected before and after 12 weeks of treatment, when HbA1c, fasting glucose, insulin, albuminuria, creatinine, total cholesterol and fractions, triglycerides, C-reactive protein, TNF-α, IL 1, 4, 5, 6, 10 and 13 will be evaluated. Anthropometric parameters and 24-hour food recall will also be evaluated. The study will evaluate the effect of taurine treatment on biochemical and anthropometric parameters in individuals with T2DM. These results will guide the decision-making to indicate taurine treatment as an adjunct in individuals with T2DM who have not reached their glycaemic goal.

Traditional Use, Phytochemical Profiles and Pharmacological Properties of Artemisia Genus from Central Asia

The flora of Kazakhstan is characterized by its wide variety of different types of medicinal plants, many of which can be used on an industrial scale. The Traditional Kazakh Medicine (TKM) was developed during centuries based on the six elements of ancient Kazakh theory, associating different fields such as pharmacology, anatomy, pathology, immunology and food nursing as well as disease prevention. The endemic Artemisia L. species are potential sources of unique and new natural products and new chemical structures, displaying diverse bioactivities and leading to the development of safe and effective phytomedicines against prevailing diseases in Kazakhstan and the Central Asia region. This review provides an overview of Artemisia species from Central Asia, particularly traditional uses in folk medicine and the recent numerous phytochemical and pharmacological studies. The review is done by the methods of literature searches in well-known scientific websites (Scifinder and Pubmed) and data collection in university libraries. Furthermore, our aim is to search for promising and potentially active Artemisia species candidates, encouraging us to analyze Protein Tyrosine Phosphatase 1B (PTP1B), α-glucosidase and bacterial neuraminidase (BNA) inhibition as well as the antioxidant potentials of Artemisia plant extracts, in which endemic species have not been explored for their secondary metabolites and biological activities so far. The main result of the study was that, for the first time, the species Artemisia scopiformis Ledeb. Artemisia albicerata Krasch., Artemisia transiliensis Poljakov, Artemisia schrenkiana Ledeb., Artemisia nitrosa Weber and Artemisia albida Willd. ex Ledeb. due to their special metabolites, showed a high potential for α-glucosidase, PTP1B and BNA inhibition, which is associated with diabetes, obesity and bacterial infections. In addition, we revealed that the methanol extracts of Artemisia were a potent source of polyphenolic compounds. The total polyphenolic contents of Artemisia extracts were correlated with antioxidant potential and varied according to plant origin, the solvent of extraction and the analytical method used. Consequently, oxidative stress caused by reactive oxygen species (ROS) may be managed by the dietary intake of current Artemisia species. The antioxidant potentials of the species A. schrenkiana, A. scopaeformis, A. transiliensis and Artemisia scoparia Waldst. & Kitam. were also promising. In conclusion, the examination of details between different Artemisia species in our research has shown that plant materials are good as an antioxidant and eznyme inhibitory functional natural source.

The effects of taurine supplementation on diabetes mellitus in humans: A systematic review and meta-analysis

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The first meta-analysis to comprehensively evaluate the effects of taurine supplementation on diabetic patients.

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Statistical significance in HbA1C, Fasting Blood Sugar, HOMA-IR after oral supplemental of taurine by diabetic patients than that of placebo.

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Taurine is expected to be a new option for the management of diabetes.

Objective

The ameliorative effect of taurine on diabetes has received extensive attention in recent years. Despite promising data from animal studies, the efficacy of taurine supplementation in human studies has been inconsistent. We thus did a meta-analysis of randomized controlled trials to assess the effect of taurine supplement on glycemic indices, serum lipids, blood pressure, body composition in patients with diabetes.

Methods

We systematically searched PubMed, Embase, Cochrane, Web of Science, FDA.gov, and ClinicalTrials.gov for randomized controlled trials (published from inception to January 15, 2022; no language restrictions) about the effect of taurine supplement on diabetes. Values of Standardized Mean Differences (SMD) were determined for continuous outcomes.

Results

Of 2206 identified studies, 5 randomized controlled trials were eligible and were included in our analysis (N = 209 participants). Compared with the control group, taurine could significantly reduce HbA1c (SMD −0.41[95% CI: −0.74, −0.09], p = 0.01), Fasting Blood Sugar (SMD − 1.28[95% CI: −2.42, −0.14], p = 0.03) and HOMA-IR (SMD − 0.64[95% CI: −1.22, −0.06], p = 0.03). In addition, taurine also reduced Insulin (SMD −0.48 [95% CI: −0.99, 0.03], p = 0.06) and TG (SMD −0.26 [95% CI: −0.55, 0.02], p = 0.07), but did not reach statistical significance.

Conclusions

Taurine supplementation is beneficial in reducing glycemic indices, such as HbA1c, Fasting Blood Sugar, HOMA-IR in diabetic patients, but has no significant effect on serum lipids, blood pressure and body composition in diabetic patients. Taurine emerges as a new option for the management of patients with diabetes. Further studies are needed to understand the potential effect of taurine in diabetic patients.

The Intestinal and Biliary Metabolites of Ibuprofen in the Rat with Experimental Hyperglycemia

Hyperglycemia is reported to be associated with oxidative stress. It can result in changes in the activities of drug-metabolizing enzymes and membrane-integrated transporters, which can modify the fate of drugs and other xenobiotics; furthermore, it can result in the formation of non-enzyme catalyzed oxidative metabolites. The present work aimed to investigate how experimental hyperglycemia affects the intestinal and biliary appearance of the oxidative and Phase II metabolites of ibuprofen in rats. In vivo studies were performed by luminal perfusion of 250 μM racemic ibuprofen solution in control and streptozotocin-treated (hyperglycemic) rats. Analysis of the collected intestinal perfusate and bile samples was performed by HPLC-UV and HPLC-MS. No oxidative metabolites could be detected in the perfusate samples. The biliary appearance of ibuprofen, 2-hydroxyibuprofen, ibuprofen glucuronide, hydroxylated ibuprofen glucuronide, and ibuprofen taurate was depressed in the hyperglycemic animals. However, no specific non-enzymatic (hydroxyl radical initiated) hydroxylation product could be detected. Instead, the depression of biliary excretion of ibuprofen and ibuprofen metabolites turned out to be the indicative marker of hyperglycemia. The observed changes impact the pharmacokinetics of drugs administered in hyperglycemic individuals.

An Observation Study of Urinary Biomarkers Exploratory in Alzheimer's Disease using High Resolution Mass Spectrometry

Alzheimer's disease (AD) is regarded as a progressive neurodegenerative dementia, characterized by degeneration of distinct neuronal populations. A case-control study was carried out by using high resolution mass spectrometry to explore AD associated urinary metabolic biomarkers from 30 AD patients and 30 cognitively normal (CN) individuals, respectively. In total, 49 metabolites were determined and validated as known compounds by LC/MS analysis. With two sample t-test statistical analysis (p<0.05), 19 metabolites were shown to be significantly differed from AD to CN. A diagnostic model of receiver-operator characteristic (ROC) curve was constructed with a combination of 9 selected metabolites and yielded a separation with an area under the curve value of 0.976 between two groups. This study indicated urinary metabolites showed a significant expression between AD and CN. AD related metabolites enable to satisfy the diagnostic power of disease discrimination. Additionally, as a non-invasive approach, urine collection provides its convenience in clinical diagnosis of AD.

Cystine uptake inhibition potentiates front-line therapies in acute myeloid leukemia

By querying metabolic pathways associated with leukemic stemness and survival in multiple AML datasets, we nominated SLC7A11 encoding the xCT cystine importer as a putative AML dependency. Genetic and chemical inhibition of SLC7A11 impaired the viability and clonogenic capacity of AML cell lines in a cysteine-dependent manner. Sulfasalazine, a broadly available drug with xCT inhibitory activity, had anti-leukemic activity against primary AML samples in ex vivo cultures. Multiple metabolic pathways were impacted upon xCT inhibition, resulting in depletion of glutathione pools in leukemic cells and oxidative stress-dependent cell death, only in part through ferroptosis. Higher expression of cysteine metabolism genes and greater cystine dependency was noted in NPM1-mutated AMLs. Among eight anti-leukemic drugs, the anthracycline daunorubicin was identified as the top synergistic agent in combination with sulfasalazine in vitro. Addition of sulfasalazine at a clinically relevant concentration significantly augmented the anti-leukemic activity of a daunorubicin-cytarabine combination in a panel of 45 primary samples enriched in NPM1-mutated AML. These results were confirmed in vivo in a patient-derived xenograft model. Collectively, our results nominate cystine import as a druggable target in AML and raise the possibility to repurpose sulfasalazine for the treatment of AML, notably in combination with chemotherapy.

Taurine Administration Counteracts Aging-Associated Impingement of Skeletal Muscle Regeneration by Reducing Inflammation and Oxidative Stress

Sarcopenia, which occurs during aging, is characterized by the gradual loss of skeletal muscle mass and function, resulting in a functional decline in physical abilities. Several factors contribute to the onset of sarcopenia, including reduced regenerative capacity, chronic low-grade inflammation, mitochondrial dysfunction, and increased oxidative stress, leading to the activation of catabolic pathways. Physical activity and adequate protein intake are considered effective strategies able to reduce the incidence and severity of sarcopenia by exerting beneficial effects in improving the muscular anabolic response during aging. Taurine is a non-essential amino acid that is highly expressed in mammalian tissues and, particularly, in skeletal muscle where it is involved in the regulation of biological processes and where it acts as an antioxidant and anti-inflammatory factor. Here, we evaluated whether taurine administration in old mice counteracts the physiopathological effects of aging in skeletal muscle. We showed that, in injured muscle, taurine enhances the regenerative process by downregulating the inflammatory response and preserving muscle fiber integrity. Moreover, taurine attenuates ROS production in aged muscles by maintaining a proper cellular redox balance, acting as an antioxidant molecule. Although further studies are needed to better elucidate the molecular mechanisms responsible for the beneficial effect of taurine on skeletal muscle homeostasis, these data demonstrate that taurine administration ameliorates the microenvironment allowing an efficient regenerative process and attenuation of the catabolic pathways related to the onset of sarcopenia.

Serum amino acid profile in chronic sinusitis

Objective: Serum amino acid profile is known to vary in many diseases. The changes in the serum amino acid profile provide important information about diagnosis and prognosis of related diseases and the effectiveness of treatment. The aim of this study is to investigate whether serum amino acids are effective in the development of CRS. Methods: A total of 23 healthy volunteers between the ages of 20 and 40 years were allocated to the control group (Group 1) and 27 patients with chronic rhinosinusitis were allocated to the study group (Group 2). The patients whose history, symptom, and examination findings were consistent with chronic sinusitis and who also who had sinusitis findings on a paranasal sinus tomography and were diagnosed with chronic sinusitis for at least one year were included in Group 2. A total of 32 serum-free amino acid levels were measured in both group using the LC-MS/MS system. Results: The serum taurine level was found to be statistically significantly lower in Group 2 compared to Group 1 (p:0.002). A significant alteration was not observed in the serum levels of remaining 31 amino acids. Conclusion: According to the data we obtained from the study, decreased serum taurine level may be a factor in the etiopathogenesis of chronic rhinosinusitis and therefore taurine supplementation may be considered as a new therapeutic target in the treatment of chronic rhinosinusitis.

Serum Metabolomics Benefits Discrimination Kidney Disease Development in Type 2 Diabetes Patients

Background

Diabetic kidney disease (DKD) is the primary cause of end-stage renal disease, raising a considerable burden worldwide. Recognizing novel biomarkers by metabolomics can shed light on new biochemical insight to benefit DKD diagnostics and therapeutics. We hypothesized that serum metabolites can serve as biomarkers in the progression of DKD.

Methods

A cross-sectional study of 1,043 plasma metabolites by untargeted LC/MS among 89 participants identified associations between proteinuria severity and metabolites difference. Pathway analysis from differently expressed metabolites was used to determine perturbed metabolism pathways. The results were replicated in an independent, cross-sectional cohort of 83 individuals. Correlation and prediction values were used to examine the association between plasma metabolites level and proteinuria amount.

Results

Diabetes, and diabetic kidney disease with different ranges of proteinuria have shown different metabolites patterns. Cysteine and methionine metabolism pathway, and Taurine and hypotaurine metabolism pathway were distinguishable in the existence of DKD in DC (diabetes controls without kidney disease), and DKD with different ranges of proteinuria. Two interesting tetrapeptides (Asn-Met-Cys-Ser and Asn-Cys-Pro-Pro) circulating levels were elevated with the DKD proteinuria progression.

Conclusions

These findings underscore that serum metabolomics provide us biochemical perspectives to identify some clinically relevant physiopathologic biomarkers of DKD progression.

Taurine: A Maternally Derived Nutrient Linking Mother and Offspring

Mammals can obtain taurine from food and synthesize it from sulfur-containing amino acids. Mammalian fetuses and infants have little ability to synthesize taurine. Therefore, they are dependent on taurine given from mothers either via the placenta or via breast milk. Many lines of evidence demonstrate that maternally derived taurine is essential for offspring development, shaping various traits in adults. Various environmental factors, including maternal obesity, preeclampsia, and undernutrition, can affect the efficacy of taurine transfer via either the placenta or breast milk. Thus, maternally derived taurine during the perinatal period can influence the offspring’s development and even determine health and disease later in life. In this review, I will discuss the biological function of taurine during development and the regulatory mechanisms of taurine transport from mother to offspring. I also refer to the possible environmental factors affecting taurine functions in mother-offspring bonding during perinatal periods. The possible functions of taurine as a determinant of gut microbiota and in the context of the Developmental Origins of Health and Disease (DOHaD) hypothesis will also be discussed.

Modulation of Fecal Metabolites by Heat Stress and Diet, and Their Association with Inflammation and Leaky Gut Markers in Dairy Cows

The analysis of fecal metabolite profiles could provide novel insights into the mechanisms underlying animal responses to environmental stressors and diet. We aimed to evaluate the effects of a 14-day heat stress period and of dietary mineral and vitamin supplementation under heat stress on fecal metabolite profiles and to investigate their associations with physiological markers of heat stress, leaky gut, and inflammation in lactating dairy cows. Twelve multiparous Holstein cows (42.2 ± 5.6 kg milk/d; 83.4 ± 27.1 DIM) were enrolled in an experiment in a split-plot design. The main plot was the level of dietary vitamin E and Se, as follows: (1) low (L-ESe; 20 IU/kg vitamin E, 0.3 ppm Se) or (2) high (H-ESe 200 IU/kg vitamin E, 1.2 ppm Se). Within each plot, six cows were randomly assigned to either (1) heat stress (HS; Total Humidity Index (THI): 82), (2) pair-feeding in thermoneutrality (TNPF; THI = 64), or (3) HS with vitamin D₃ and Ca supplementation (HS+DCa; 1820 IU/kg and 1.5% Ca; THI: 82) in a replicated 3 × 3 Latin square design with 14-day periods and 7-day washouts. The concentrations of 94 metabolites were determined in fecal samples, including amino acids, fatty acids, biogenic amines, and vitamins. Relative to the L-ESe group, the H-ESe group increased α-tocopherol by threefold, whereas δ-tocopherol was decreased by 78% (P_FDR < 0.01). Nevertheless, correlation analysis between α-tocopherol and all the others fecal metabolites or physiological heat stress measures did not show significant associations. No interactions between main plot and treatments were observed. Relative to TNPF, HS increased plasma tumor necrosis factor-alpha (TNF-α), plasma lipopolysaccharide-binding protein (LBP), milk somatic cell counts (SCC), respiratory rates, rectal temperatures, fecal tridecylic and myristic acids, vitamin B₇, and retinol, whereas it decreased fecal amino acids such as histidine, methyl histidine, acetyl ornithine, and arginine (P_FDR < 0.05). In contrast, HS+DCa increased fecal methyl histidine concentrations and reduced milk SCC, plasma TNF-α, and LBP, as well as rectal temperatures. Discriminant analysis revealed fecal histidine, taurine, acetyl ornithine, arginine, β-alanine, ornithine, butyric + iso-butyric acid, plasma non-esterified fatty acids, TNF-α, LBP, C-reactive protein, and milk SCC were predictive of HS. Several metabolites were predictive of HS+DCa, although only tryptophan was discriminant relative to HS. In conclusion, both heat stress and the supplementation of vitamin D₃ and Ca can influence the fecal metabolome of dairy cows experiencing heat stress, independently of dietary levels of vitamin E and Se. Our results suggest that some fecal metabolites are well associated with physiological measures of heat stress and may thus provide insights into the gut-level changes taking place under heat stress in dairy cows.

Recent insights into the molecular regulators and mechanisms of taurine to modulate lipid metabolism: a review

Lipid metabolism disorders such as hypertriglyceridemia and hypercholesterolemia are risk factors for cardiovascular diseases and atherosclerosis that are grave public health issues. Taurine, a sulfur-containing non-essential amino acid exerts a wide range of physiological effects that regulate lipid metabolic disorders. Although the effects of taurine on lipid-lowering have been reported in animals and humans, mechanisms elucidating the lipid-lowering action of taurine remain unclear. A series of molecular regulators associated with lipid metabolism have been identified in the past few decades. These include nuclear receptors, transcription factors, and enzymes that undergo important changes during taurine treatment. In this review, we focus on the role of taurine in lipid metabolism and discuss taurine-related interventions in combating lipid disorders.

Next-Generation Genetic and Fermentation Technologies for Safe and Sustainable Production of Food Ingredients: Colors and Flavorings

A growing human population is a significant issue in food security owing to the limited land and resources available for agricultural food production. To solve these problems, sustainable food manufacturing processes and the development of alternative foods and ingredients are needed. Metabolic engineering and synthetic biology can help solve the food security issue and satisfy the demand for alternative food production. Bioproduction of food ingredients by microbial fermentation is a promising method to replace current manufacturing processes, such as extraction from natural materials and chemical synthesis, with more ecofriendly and sustainable operations. This review highlights successful examples of bioproduction for food additives by engineered microorganisms, with an emphasis on colorants and flavors that are extensively used in the food industry. Recent strain engineering developments and fermentation strategies for producing selected food colorants and flavors are introduced with discussions on the current status and future perspectives.

Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

A systematic review of preclinical studies on the taurine role during diabetic nephropathy: focused on anti-oxidative, anti-inflammation, and anti-apoptotic effects

Diabetic nephropathy is one of the most important and growing diseases globally and the leading cause of cardiovascular mortality in these patients. Taurine is an amino acid that has pleiotropic protective properties on some diseases. This study aimed to investigate the potential role of taurine in the treatment of diabetes-induced nephropathy. To achieve the aim of the present study, a comprehensive systematic search based on PRISMA guidelines has been conducted up to August 2021. A total of 382 articles were found in the electronic databases based on search keywords. After doing the screening, 14 articles were included in the present systematic review. The dated demonstrated elevation of oxidative stress, inflammatory and apoptotic pathways, and changes in other molecules' function plays an essential role in diabetes-induced renal tissue damage. Due to its multiple protective effects, taurine significantly prevented the activation of the pathways mentioned above and altered the function of molecules involved in these pathways, resulting in alleviating diabetic nephropathy. According to the obtained results, it was found that taurine can mitigate diabetes-induced nephropathy, mainly through its anti-oxidant activity, which is an essential factor in activating inflammation and apoptosis pathways.

In situ Metabolomics of Metabolic Reprogramming Involved in a Mouse Model of Type 2 Diabetic Kidney Disease

The in situ metabolic profiling of the kidney is crucial to investigate the complex metabolic reprogramming underlying diabetic kidney disease (DKD) and to allow exploration of potential metabolic targets to improve kidney function. However, as the kidney is a highly heterogeneous organ, traditional metabolomic methods based on bulk analysis that produce an averaged measurement are inadequate. Herein, we employed an in situ metabolomics approach to discover alternations of DKD-associated metabolites and metabolic pathways. A series of histology-specific metabolic disturbances were discovered in situ using airflow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI). In combination with integrated metabolomics analysis, five dysfunctional metabolic pathways were identified and located in the kidneys of type-2 DKD mice simultaneously for the first time, including taurine metabolism, arginine and proline metabolism, histidine metabolism, biosynthesis of unsaturated fatty acids, and fatty acid degradation pathways. As crucial nodes of metabolic pathways, five dysregulated rate-limiting enzymes related to altered metabolic pathways were further identified. These findings reveal alternations from metabolites to enzymes at the molecular level in the progression of DKD and provide insights into DKD-associated metabolic reprogramming.

Taurine as a Natural Antioxidant: From Direct Antioxidant Effects to Protective Action in Various Toxicological Models

Natural antioxidants have received tremendous attention over the last 3 decades. At the same time, the attitude to free radicals is slowly changing, and their signalling role in adaptation to stress has recently received a lot of attention. Among many different antioxidants in the body, taurine (Tau), a sulphur-containing non-proteinogenic β-amino acid, is shown to have a special place as an important natural modulator of the antioxidant defence networks. Indeed, Tau is synthesised in most mammals and birds, and the Tau requirement is met by both synthesis and food/feed supply. From the analysis of recent data, it could be concluded that the direct antioxidant effect of Tau due to scavenging free radicals is limited and could be expected only in a few mammalian/avian tissues (e.g., heart and eye) with comparatively high (>15-20 mM) Tau concentrations. The stabilising effects of Tau on mitochondria, a prime site of free radical formation, are characterised and deserve more attention. Tau deficiency has been shown to compromise the electron transport chain in mitochondria and significantly increase free radical production. It seems likely that by maintaining the optimal Tau status of mitochondria, it is possible to control free radical production. Tau's antioxidant protective action is of great importance in various stress conditions in human life, and is related to commercial animal and poultry production. In various in vitro and in vivo toxicological models, Tau showed AO protective effects. The membrane-stabilizing effects, inhibiting effects on ROS-producing enzymes, as well as the indirect AO effects of Tau via redox balance maintenance associated with the modulation of various transcription factors (e.g., Nrf2 and NF-κB) and vitagenes could also contribute to its protective action in stress conditions, and thus deserve more attention.

Blueberry Counteracts Prediabetes in a Hypercaloric Diet-Induced Rat Model and Rescues Hepatic Mitochondrial Bioenergetics

The paramount importance of a healthy diet in the prevention of type 2 diabetes is now well recognized. Blueberries (BBs) have been described as attractive functional fruits for this purpose. This study aimed to elucidate the cellular and molecular mechanisms pertaining to the protective impact of blueberry juice (BJ) on prediabetes. Using a hypercaloric diet-induced prediabetic rat model, we evaluated the effects of BJ on glucose, insulin, and lipid profiles; gut microbiota composition; intestinal barrier integrity; and metabolic endotoxemia, as well as on hepatic metabolic surrogates, including several related to mitochondria bioenergetics. BJ supplementation for 14 weeks counteracted diet-evoked metabolic deregulation, improving glucose tolerance, insulin sensitivity, and hypertriglyceridemia, along with systemic and hepatic antioxidant properties, without a significant impact on the gut microbiota composition and related mechanisms. In addition, BJ treatment effectively alleviated hepatic steatosis and mitochondrial dysfunction observed in the prediabetic animals, as suggested by the amelioration of bioenergetics parameters and key targets of inflammation, insulin signaling, ketogenesis, and fatty acids oxidation. In conclusion, the beneficial metabolic impact of BJ in prediabetes may be mainly explained by the rescue of hepatic mitochondrial bioenergetics. These findings pave the way to support the use of BJ in prediabetes to prevent diabetes and its complications.

Taurine: A Water Friendly Organocatalyst in Organic Reactions

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Organocatalysis has become a powerful tool in organic synthesis for the formation of C-C and C-X (N, S, O, etc.) bonds, leading to the formation of complex molecules from easily available starting materials. It provides an alternative platform to the conventional synthesis and fulfills the principles of green chemistry. During the last decades, taurine has emerged as a promising organocatalyst in an array of organic transformations in addition to its plentiful biological properties. It is highly stable, easy to store and separate, water-soluble, of low cost, easily available, and recyclable. The present article highlights the recent and up-to-date applications of taurine in organic transformations.

Irisin restores high glucose-induced cell injury in vascular endothelial cells by activating Notch pathway via Notch receptor 1

Diabetic foot ulcers (DFU) are a vascular complication of diabetes mellitus (DM). It has been confirmed that irisin is closely related to DM. However, the effect of irisin on DFU is obscure and needs further study. After human umbilical vein endothelial cell lines (HUVECs) were treated with different concentrations' irisin, normal glucose, high glucose (HG), HG plus irisin-high (H) or sh-Notch1, cell biological behaviors, LDH, and VEGFA were detected by cell function experiments. Apoptosis- and Notch pathway-related protein levels were evaluated by Western blot. Irisin has no cytotoxicity, and irisin-H elevated cell viability and inhibited apoptosis and LDH level in HG-induced HUVECs. Meanwhile, irisin-H restored HG-repressed migration and angiogenesis in HUVECs. Irisin-H inhibited apoptosis-related protein levels and promoted VEGFA and Notch pathway-related protein levels in HG-treated HUVECs. Additionally, sh-Notch1 reversed the protective effect of irisin-H in HG-treated HUVECs. Irisin restores HG-induced cell injury and angiogenesis in HUVECs by activating Notch pathway via Notch1.

Investigating the genetic architecture of disease resilience in pigs by genome-wide association studies of complete blood count traits collected from a natural disease challenge model

Background

Genetic improvement for disease resilience is anticipated to be a practical method to improve efficiency and profitability of the pig industry, as resilient pigs maintain a relatively undepressed level of performance in the face of infection. However, multiple biological functions are known to be involved in disease resilience and this complexity means that the genetic architecture of disease resilience remains largely unknown. Here, we conducted genome-wide association studies (GWAS) of 465,910 autosomal SNPs for complete blood count (CBC) traits that are important in an animal’s disease response. The aim was to identify the genetic control of disease resilience.

Results

Univariate and multivariate single-step GWAS were performed on 15 CBC traits measured from the blood samples of 2743 crossbred (Landrace × Yorkshire) barrows drawn at 2-weeks before, and at 2 and 6-weeks after exposure to a polymicrobial infectious challenge. Overall, at a genome-wise false discovery rate of 0.05, five genomic regions located on Sus scrofa chromosome (SSC) 2, SSC4, SSC9, SSC10, and SSC12, were significantly associated with white blood cell traits in response to the polymicrobial challenge, and nine genomic regions on multiple chromosomes (SSC1, SSC4, SSC5, SSC6, SSC8, SSC9, SSC11, SSC12, SSC17) were significantly associated with red blood cell and platelet traits collected before and after exposure to the challenge. By functional enrichment analyses using Ingenuity Pathway Analysis (IPA) and literature review of previous CBC studies, candidate genes located nearby significant single-nucleotide polymorphisms were found to be involved in immune response, hematopoiesis, red blood cell morphology, and platelet aggregation.

Conclusions

This study helps to improve our understanding of the genetic basis of CBC traits collected before and after exposure to a polymicrobial infectious challenge and provides a step forward to improve disease resilience.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07835-4.

Neuroprotective Effect of Taurine against Cell Death, Glial Changes, and Neuronal Loss in the Cerebellum of Rats Exposed to Chronic-Recurrent Neuroinflammation Induced by LPS

The present study investigated the neuroprotective effect of taurine against the deleterious effects of chronic-recurrent neuroinflammation induced by LPS in the cerebellum of rats. Adult male Wistar rats were treated with taurine for 28 days. Taurine was administered at a dose of 30 or 100 mg/kg, by gavage. On days 7, 14, 21, and 28, the animals received LPS (250 μg/kg) intraperitoneally. The vehicle used was saline. The animals were divided into six groups: vehicle, taurine 30 mg/kg, taurine 100 mg/kg, LPS, LPS plus taurine 30 mg/kg, and LPS plus taurine 100 mg/kg. On day 29, the animals were euthanized, and the cerebellum was removed and prepared for immunofluorescence analysis using antibodies of GFAP, NeuN, CD11b, and cleaved caspase-3. LPS group showed a reduction in the immunoreactivity of GFAP in the arbor vitae and medullary center and of NeuN in the granular layer of the cerebellar cortex. LPS increased the immunoreactivity of CD11b in the arbor vitae and in the medullary center. Taurine protected against these effects induced by LPS in immunoreactivity of GFAP, NeuN, and CD11b, with the 100 mg/kg dose being the most effective. LPS induced an increase in the number of positive cleaved caspase-3 cells in the Purkinje cell layers, granular layer, arbor vitae, and medullary center. Taurine showed its antiapoptotic activity by reducing the cleaved caspase-3 cells in relation to the LPS group. Here, a potential neuroprotective role of taurine can be seen since this amino acid was effective in protecting the cerebellum of rats against cell death and changes in glial and neuronal cells in the face of chronic-recurrent neuroinflammation.

Biomarker identification and pathway analysis of rheumatoid arthritis based on metabolomics in combination with ingenuity pathway analysis

Rheumatoid arthritis (RA) is a common autoimmune and inflammatory disease worldwide, but understanding its pathogenesis is still limited. In this study, plasma untargeted metabolomics of a discovery cohort and targeted analysis of a verification cohort were performed by gas chromatograph mass spectrometry (GC/MS). Univariate and multivariate statistical analysis were utilized to reveal differential metabolites, followed by the construction of biomarker panel through random forest (RF) algorithm. The pathways involved in RA were enriched by differential metabolites using Ingenuity Pathway Analysis (IPA) suite. Untargeted metabolomics revealed eighteen significantly altered metabolites in RA. Among these metabolites, a three-metabolite marker panel consisting of L-cysteine, citric acid and L-glutamine was constructed, using random forest algorithm that could predict RA with high accuracy, sensitivity and specificity based on a multivariate exploratory receiver operator characteristic (ROC) curve analysis. The panel was further validated by support vector machine (SVM) and partial least squares discriminant analysis (PLS-DA) algorithms, and also verified with targeted metabolomics using a verification cohort. Additionally, the dysregulated taurine biosynthesis pathway in RA was revealed by an integrated analysis of metabolomics and transcriptomics. Our findings in this study not only provided a mechanism underlying RA pathogenesis, but also offered alternative therapeutic targets for RA.

Disparate Metabolomic Responses to Fructose Consumption between Different Mouse Strains and the Role of Gut Microbiota

High fructose consumption has been linked to metabolic syndrome, yet the fructose-induced phenotypes, gene expression, and gut microbiota alterations are distinct between mouse strains. In this study, we aim to investigate how fructose consumption shapes the metabolomic profiles of mice with different genetic background and microbiome. We used fructose-sensitive DBA/2J (DBA) and fructose-resistant C57BL/6J (B6) mice given 8% fructose or regular water for 12 weeks. Plasma and fecal metabolites were profiled using a liquid chromatography-tandem mass spectrometry based global metabolomic approach. We found that the baseline metabolomic profiles were different between DBA and B6 mice, particularly plasma metabolites involved in lipid metabolism and fecal metabolites related to dipeptide/amino acid metabolism. In response to fructose, DBA mice showed a distinct decrease of plasma branched chain fatty acids with concordantly increased branched chain amino acids, which were correlated with adiposity; B6 mice had significantly increased plasma cholesterol and total bile acids, accompanied by decreased fecal levels of farnesoid X receptor antagonist tauro-β-muricholate, which were correlated with fructose-responsive bacteria Dehalobacterium, Magibacteriaceae, and/or Akkermansia. Our results demonstrate that baseline metabolomic profiles differ and respond differentially to fructose between mice with different genetic background and gut microbiota, which may play a role in individualized risks to fructose-induced metabolic syndrome.

Taurine Protects C2C12 Myoblasts From Impaired Cell Proliferation and Myotube Differentiation Under Cisplatin-Induced ROS Exposure

In cancer patients, chemotherapeutic medication induces aberrant ROS (reactive oxygen species) accumulation in skeletal muscles, resulting in myofiber degradation, muscle weakness, and even cachexia, which further leads to poor therapeutic outcomes. Acting as an antioxidant, taurine is extensively used to accelerate postexercise muscle recovery in athletes. The antioxidant effects of taurine have been shown in mature myotubes and myofibers but not yet in myoblasts, the myotube precursor. The proliferation and differentiation ability of myoblasts play a very important role in myofiber repair and regeneration, which is usually impaired during chemotherapeutics in cancer patients as well. Here, we explored the effects of taurine supplementation on C2C12 myoblasts exposed to cisplatin-induced ROS. We found that cisplatin treatment led to dramatically decreased cell viability; accumulated ROS level; down-regulated expressions of MyoD1 (myoblast determination protein 1), myogenin, and MHC (myosin heavy chain); and impaired myotube differentiation in myoblasts. Significantly, taurine supplementation protected myoblasts against cisplatin-induced cell viability decrease, promoted cellular ROS clearance, and, most importantly, preserved the expressions of MyoD1, myogenin, and MHC as well as myotube differentiation ability. We further conducted NMR-based metabolomic analysis to clarify the underlying molecular mechanisms. We identified 14 characteristic metabolites primarily responsible for the discrimination of metabolic profiles between cisplatin-treated cells and normal counterparts, including increased levels of BCAAs (branched-chain amino acids: leucine and isoleucine), alanine, glycine, threonine, glucose, ADP (adenosine diphosphate), phenylalanine, and PC (O-phosphocholine), and decreased levels of lysine, β-alanine, choline, GPC (sn-glycero-3-phosphocholine), and myo-inositol. Evidently, taurine supplementation partially reversed the changing trends of several metabolites (isoleucine, threonine, glycine, PC, β-alanine, lysine, and myo-inositol). Furthermore, taurine supplementation promoted the proliferation and myotube differentiation of myoblasts by alleviating cellular catabolism, facilitating GSH (reduced glutathione) biosynthesis, improving glucose utilization and TCA (tricarboxylic acid) cycle anaplerosis, and stabilizing cellular membranes. Our results demonstrated the protective effects of taurine on cisplatin-impaired myoblasts and elucidated the mechanistic rationale for the use of taurine to ameliorate muscle toxicity in clinical chemotherapy cancer patients.

A systematic review of preclinical studies on the efficacy of taurine for the treatment of rheumatoid arthritis

Due to the undesirable effects of conventional medical therapies prescribed for rheumatoid arthritis (RA), complementary therapies, especially nutritional agents, have recently gained great attention. Recent animal and in vitro researches have shown benefits of taurine (Tau), a sulfur-containing amino acid, in RA and suggest that Tau may be a therapeutic candidate in RA; however, no systematic review exists regarding Tau and RA. Accordingly, this paper systematically reviewed the available researches regarding Tau and RA and plausible underlying mechanisms. We searched electronic databases like Scopus, WOS, PubMed, Embase, ProQuest, Cochrane Library, and a search engine Google Scholar until December 2020 and we have applied search alert services to detect related papers published after the primary search. We did not have any restriction in publication date and/or language. We found no clinical study; thus we considered related animal and in vitro researches. Furthermore, we checked the citations or references of these researches and grey literature to detect possible studies. We did not consider reviews, book chapters, conference abstracts, and articles about Tau in health problems other than RA. Eighteen articles were entered in present systematic review. Animal and in vitro researches showed that Tau either directly or indirectly (via Tau derivatives such as Tau-chloramine, Tau-bromamine, taurochenodeoxycholic acid, and taurolidine) could control RA by different mechanisms such as reducing inflammation, suppressing oxidative stress, and inducing apoptosis. This review serves convincing clues about the efficacy of Tau in RA and explains the importance of additional clinical investigations.

Hyperreflexia and enhanced ripple oscillations in the taurine-deficient mice

In this study, we examined neuronal excitability and skeletal muscle physiology and histology in homozygous knockout mice lacking cysteine sulfonic acid decarboxylase (CSAD-KO). Neuronal excitability was measured by intracerebral recording from the prefrontal cortex. Skeletal muscle response was measured through stretch reflex in the ankle muscles. Specifically, we measured the muscle tension, amplitude of electromyogram and velocity of muscle response. Stretch reflex responses were evoked using a specialized stretching device designed for mice. The triceps surae muscle was stretched at various speeds ranging from 18 to 18,000° s^-1. A transducer recorded the muscle resistance at each velocity and the corresponding EMG. We also measured the same parameter in anesthetized mice. We found that at each velocity, the CSAD-KO mice generated more tension and exhibited higher EMG responses. To evaluate if the enhanced response was due to neuronal excitability or changes in the passive properties of muscles, we anesthetize mice to eliminate the central component of the reflex. Under these conditions, CSAD-KO mice still exhibited an enhanced stretch reflex response, indicating ultrastructural alterations in muscle histology. Consistent with this, we found that sarcomeres from CSAD-KO muscles were shorter and thinner when compared to control sarcomeres. Neuronal excitability was further investigated using intracerebral recordings of brain waves from the prefrontal cortex. We found that extracellular field potentials in CSAD-KO mice were characterized by reduced amplitude of low-frequency brain waves (delta, theta, alpha, beta and gamma) and increased in the high low-frequency brain waves (slow and fast ripples). Increased slow and fast ripple rates serve as a biomarker of epileptogenic brain. We have previously shown that taurine interacts with GABA_A receptors and induces biochemical changes in the GABAergic system. We suggest that taurine deficiency leads to alterations in the GABAergic system that contribute to the enhanced stretch reflex in CSAD-KO mice through biochemical mechanisms that involve alterations not only at the spinal level but also at the cortical level.

In Vivo and In Vitro Assays Evaluating the Biological Activity of Taurine, Glucose and Energetic Beverages

Taurine is one of the main ingredients used in energy drinks which are highly consumed in adolescents for their sugary taste and stimulating effect. With energy drinks becoming a worldwide phenomenon, the biological effects of these beverages must be evaluated in order to fully comprehend the potential impact of these products on the health due to the fact nutrition is closely related to science since the population consumes food to prevent certain diseases. Therefore, the aim of this study was to evaluate the biological effects of taurine, glucose, classic Red Bull® and sugar-free Red Bull® in order to check the food safety and the nutraceutical potential of these compounds, characterising different endpoints: (i) Toxicology, antitoxicology, genotoxicology and life expectancy assays were performed in the Drosophila melanogaster model organism; (ii) The in vitro chemopreventive activity of testing compounds was determined by assessing their cytotoxicity, the proapoptotic DNA-damage capability to induce internucleosomal fragmentation, the strand breaks activity and the modulator role on the methylation status of genomic repetitive sequences of HL-60 promyelocytic cells. Whereas none tested compounds showed toxic or genotoxic effect, all tested compounds exerted antitoxic and antigenotoxic activity in Drosophila. Glucose, classic Red Bull® and sugar-free Red Bull® were cytotoxic in HL-60 cell line. Classic Red Bull® induced DNA internucleosomal fragmentation although none of them exhibited DNA damage on human leukaemia cells. In conclusion, the tested compounds are safe on Drosophila melanogaster and classic Red Bull® could overall possess nutraceutical potential in the in vivo and in vitro model used in this study. Besides, taurine could holistically be one of the bioactive compounds responsible for the biological activity of classic Red Bull®.

Protective Effects of Taurine Chloramine on Experimentally Induced Colitis: NFκB, STAT3, and Nrf2 as Potential Targets

Taurine chloramine (TauCl) is an endogenous anti-inflammatory substance which is derived from taurine, a semi-essential sulfur-containing β-amino acid found in some foods including meat, fish, eggs and milk. In general, TauCl as well as its parent compound taurine downregulates production of tissue-damaging proinflammatory mediators, such as chemokines and cytokines in many different types of cells. In the present study, we investigated the protective effects of TauCl on experimentally induced colon inflammation. Oral administration of TauCl protected against mouse colitis caused by 2,4,6-trinitrobenzene sulfonic acid (TNBS). TauCl administration attenuated apoptosis in the colonic mucosa of TNBS-treated mice. This was accompanied by reduced expression of an oxidative stress marker, 4-hydroxy-2-nonenal and proinflammatory molecules including tumor necrosis factor-α, interleukin-6 and cyclooxygenase-2 in mouse colon. TauCl also inhibited activation of NFκB and STAT3, two key transcription factors mediating proinflammatory signaling. Notably, the protective effect of TauCl on oxidative stress and inflammation in the colon of TNBS-treated mice was associated with elevated activation of Nrf2 and upregulation of its target genes encoding heme oxygenase-1, NAD(P)H:quinone oxidoreductase, glutamate cysteine ligase catalytic subunit, and glutathione S-transferase. Taken together, these results suggest that TauCl exerts the protective effect against colitis through upregulation of Nrf2-dependent cytoprotective gene expression while blocking the proinflammatory signaling mediated by NFκB and STAT3.